Method for measuring the coaxiality of the rotating part of a model pump-turbine

Abstract

The present application relates to the technical field of water turbine installation, and discloses a method for measuring the coaxiality of a rotating part of a model water pump water turbine, comprising the following steps: step 1, calibrating the coaxiality of a runner and a joint flange combination; step 2, placing the combination into a tool device, coupling with a static pressure bearing and leaving a measurement space; and step 3, calibrating the coaxiality of a lower comb tooth ring surface, a lower ring outer ring sealing surface, an upper crown outer ring sealing surface and an upper comb tooth ring surface of the runner. The method avoids mutual scratching of the sealing surface of the upper crown of the runner and the top cover and the comb tooth surface.

Description

Technical Field

[0001] This invention relates to the field of water turbine installation technology, and specifically to a method for measuring the coaxiality of the rotating parts of a model water pump turbine. Background Technology

[0002] The accuracy of the coaxiality of the turbine runner is crucial for the operation of the turbine. If the coaxiality deviation is too large, the runner vibration will increase, which may lead to vibration of the unit or bearings, further causing the clearance to widen, damaging the turbine generator, reducing the hydrodynamic performance of the turbine, and affecting the power generation efficiency.

[0003] Chinese patent document CN119146837A discloses an auxiliary measuring fixture and method for measuring the coaxiality of a turbine runner. The auxiliary measuring fixture includes fasteners, supports, a piano wire, a counterweight, an oil drum, and an inside micrometer. In this invention, the turbine runner is placed on a horizontal surface and its horizontality is adjusted to within 0.02 mm / m. The turbine main shaft is connected to the turbine runner via fasteners, and its verticality is adjusted to within 0.02 mm / m. Supports are symmetrically installed on the turbine main shaft journal in the XY direction. One end of the piano wire is fixedly wound around the top of the support, and the other end of the piano wire is equipped with a counterweight suspended inside the oil drum. The shortest distances from the turbine main shaft journal to the piano wire, from the upper crown of the turbine runner to the piano wire, and from the lower ring of the turbine runner to the piano wire are measured using an inside micrometer.

[0004] Currently, when conducting model experiments, such as Figure 1 As shown, when installing the pump-turbine model device, the volute, guide vane mechanism, and hydrostatic bearing assembly are first hoisted onto the test bench for hydraulic torque measurement. A dial indicator is placed at the lower bearing interface of the hydrostatic bearing to measure the coaxiality of the top cover and bottom ring sealing surfaces. Then, the runner and coupling flange assembly is mounted onto the lower bearing interface of the hydrostatic bearing, and the coaxiality of the rotating parts is measured again using a dial indicator. During model testing, the sealing surfaces and comb tooth surfaces of the runner crown and top cover are prone to rubbing against each other. Summary of the Invention

[0005] To address the technical problem of easy rubbing between the sealing surfaces and comb tooth surfaces of the crown and top cover of a turbine runner, this invention provides a method for measuring the coaxiality of the rotating parts of a model water pump turbine, comprising the following steps: Step 1: Calibrate the coaxiality of the assembly of the impeller and the coupling flange; Step 2: Place the assembly into the tooling device and connect it to the hydrostatic bearing, leaving space for measurement; Step 3: Perform coaxiality calibration on the lower comb tooth ring surface, the lower outer ring sealing surface, the upper crown outer ring sealing surface, and the upper comb tooth ring surface of the rotor.

[0006] Preferably, in step 3, the coaxiality of the lower comb tooth ring surface, the lower outer ring sealing surface, the upper crown outer ring sealing surface, and the upper comb tooth ring surface of the rotating wheel is calibrated.

[0007] Preferably, in step 2, the hydrostatic bearing is installed on the top of the tooling device and its end is inserted into the tooling device, and the assembly is connected to the end of the hydrostatic bearing.

[0008] Preferably, the tooling device includes an upper ring plate, a lower ring plate, and supporting stiffeners. The upper ring plate and the lower ring plate are connected by multiple supporting stiffeners, and a space for dial indicator measurement is formed between the upper ring plate and the lower ring plate.

[0009] To facilitate the installation and measurement of the dial indicator, the upper ring plate is smaller than the lower ring plate, and the supporting rib is a curved rib.

[0010] To facilitate the installation of the assembly and the connection between the assembly and the hydrostatic bearing, both the upper and lower ring plates are provided with through holes in the middle.

[0011] If the coaxiality in step 3 cannot be satisfied, in order to improve the accuracy of the hydraulic torque measurement, if the coaxiality of the impeller in step 4 is not satisfied, the impeller is disassembled, an impeller pad is installed between the impeller and the hydrostatic bearing, a thin copper sheet is inserted into the upper end face of the impeller pad, and then step 3 is repeated again.

[0012] Furthermore, in step 5, if the coaxiality of the impeller is not satisfied, readjust the coaxiality of the impeller and the coupling flange assembly, and repeat steps 3 and 4.

[0013] The present invention has the following beneficial effects: 1. In existing technologies, due to interference between the top cover and bottom ring on the test bench, the coaxiality of the lower outer ring sealing surface, upper crown outer ring sealing surface, and upper comb tooth ring surface of the impeller cannot be calibrated using a dial indicator. Only the coaxiality of the lower comb tooth ring surface of the impeller can be calibrated. Therefore, the accuracy of the coaxiality of the impeller, coupling flange, and hydrostatic bearing cannot be guaranteed. This invention pre-assembles and measures the coaxiality of the rotating parts of the model water pump turbine. By pre-assembling and confirming the coaxiality of the impeller, coupling flange, and hydrostatic bearing through a tooling device, the impeller is subsequently installed on the test bench. The sealing surfaces of the upper crown and top cover, as well as the comb tooth surfaces, do not rub against each other, ensuring smooth rotation of the impeller without frictional obstruction and preventing the introduction of frictional torque. This ensures the accuracy of the measured hydraulic torque of the impeller on the test bench. Attached Figure Description

[0014] Figure 1 A schematic diagram of the hydraulic torque of the turbine runner on the test bench; Figure 2 This is a schematic diagram of step 1 in an embodiment of the present invention; Figure 3 This is a schematic diagram of step 2 in an embodiment of the present invention; Figure 4 This is a schematic diagram of step 3 in an embodiment of the present invention; Figure 5 This is a schematic diagram of step 4 in an embodiment of the present invention; Figure 6 This is a schematic diagram of steps 5 and 6 in an embodiment of the present invention; Figure 7 This is a schematic diagram of the tooling device in an embodiment of the present invention; Figure 8 for Figure 7 Top view. Detailed Implementation

[0015] The following detailed description illustrates the specific implementation method: Those skilled in the art will understand that hydrostatic bearings are sliding bearings in which a pressure pump forcibly pumps pressure lubricant into the tiny gap between the bearing and the shaft. The working principle of a hydrostatic bearing is that the pressure lubricant forms a lubricating film between the bearing and the shaft, thereby reducing friction and wear. Specifically, a hydrostatic bearing has oil chambers on its inner surface, and a pressure pump pumps lubricant into these chambers. When the bearing is under load, the lubricant in the oil chambers creates a pressure difference, which lifts the shaft, surrounding it within the oil chambers, thus forming liquid lubrication.

[0016] The reference numerals in the accompanying drawings of the instruction manual include: 1. Rotary wheel; 2. Coupling flange; 3. Tooling device; 301. Upper ring plate; 302. Lower ring plate; 303. Support rib plate; 304. Through hole; 4. Hydrostatic bearing; 5. Rotary wheel pad; 6. Lower comb tooth ring surface; 7. Lower ring outer ring sealing surface; 8. Upper crown outer ring sealing surface; 9. Upper comb tooth ring surface; 10. Test bench; 11. Bottom ring; 12. Top cover; 13. Rotary wheel upper crown; 14. Dial indicator.

[0017] Example 1 like Figure 2-8 As shown, a method for measuring the coaxiality of the rotating parts of a model water pump turbine includes the following steps: Step 1: Pre-assemble the impeller 1 and coupling flange 2 into a joint, and use a dial indicator to calibrate the coaxiality of the joint; Step 2: Place the assembly into the space formed between the upper ring plate 301 and the lower ring plate 302 of the tooling device 3; Step 3: The hydrostatic bearing 4 is installed on top of the tooling device 3 and its end is inserted into the space of the tooling device 3; Step 4: Connect the assembly to the end of the hydrostatic bearing 4; Step 5: Slowly rotate the wheel 1 and use the dial indicator 14 to calibrate the coaxiality of the lower comb tooth ring surface 6, the lower outer ring sealing surface 7, the upper crown outer ring sealing surface 8, and the upper comb tooth ring surface 9 of the wheel 1 in the tooling device 3. Step 6: If the coaxiality deviation cannot be controlled within ±0.05mm, disassemble the rotating wheel 1, install the rotating wheel pad 5 between the rotating wheel 1 and the hydrostatic bearing 4, insert a thin copper sheet into the upper end face of the rotating wheel pad 5, slowly rotate the rotating wheel 1, and use the dial indicator 14 in the tooling device 3 to calibrate the coaxiality of the lower comb tooth ring surface 6, the lower outer ring sealing surface 7, the upper crown outer ring sealing surface 8 and the upper comb tooth ring surface 9 of the rotating wheel 1 respectively. Step 7: If the coaxiality deviation cannot be controlled within ±0.05mm, readjust the coaxiality of the assembly of the rotating wheel 1 and the coupling flange 2 by adjusting the connecting bolts of the rotating wheel 1 and the coupling flange 2. Repeat steps 5 and 6 until the coaxiality of the lower comb tooth ring surface 6, the lower outer ring sealing surface 7, the upper crown outer ring sealing surface 8, and the upper comb tooth ring surface 9 of the rotating wheel 1 is controlled within ±0.05mm. Step 8: Install the calibrated coaxiality wheel 1, coupling flange 2, and hydrostatic bearing 4 on the test bench 10 to conduct a model experiment.

[0018] The tooling device 3 includes an upper ring plate 301, a lower ring plate 302, and a support rib 303. The upper ring plate 301 and the lower ring plate 302 are connected by multiple support ribs 303, and a space is formed between the upper ring plate 301 and the lower ring plate 302 for the dial indicator 14 to measure. The size of the upper ring plate 301 is smaller than that of the lower ring plate 302, and the support rib 303 is a rib with an arc.

[0019] Both the upper ring plate 301 and the lower ring plate 302 are provided with through holes 304 in the middle to facilitate the installation of the assembly and the connection between the assembly and the hydrostatic bearing 4.

[0020] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for measuring the coaxiality of the rotating parts of a model water pump turbine, characterized in that, Includes the following steps: Step 1: Calibrate the coaxiality of the rotor and coupling flange assembly; Step 2: Place the assembly into the tooling device and connect it to the hydrostatic bearing, leaving space for measurement. The hydrostatic bearing is installed on the top of the tooling device and its end is inserted into the tooling device. Connect the assembly to the end of the hydrostatic bearing. The tooling device includes an upper ring plate, a lower ring plate, and supporting ribs. The upper ring plate and the lower ring plate are connected by multiple supporting ribs. A space for dial indicator measurement is formed between the upper ring plate and the lower ring plate. The size of the upper ring plate is smaller than that of the lower ring plate. The supporting ribs are curved ribs. Both the upper ring plate and the lower ring plate have through holes in the middle. Step 3: Perform coaxiality calibration on the lower comb tooth ring surface, the lower outer ring sealing surface, the upper crown outer ring sealing surface, and the upper comb tooth ring surface of the rotor; Step 4: If the coaxiality of the roller is not satisfied, remove the roller and install a roller pad between the roller and the hydrostatic bearing. Insert a thin copper sheet into the upper end of the roller pad and then repeat step 3. Step 5: If the coaxiality of the impeller is not met, readjust the coaxiality of the impeller and coupling flange assembly, and repeat steps 3 and 4.

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